It seems obvious enough: At some point, gasoline will get so expensive that gas-guzzling drivers of all stripes will consider purchasing electric cars. But how expensive does gas have to be before this happens? No one is really sure.

The most recent study on the subject comes from Harvard’s Kennedy School, which predicts that significant market penetration of EVs will come when gas prices hit approximately $4.50 per gallon. This is the tipping point, the authors explain, because it will make EVs competitive across a wide range of features, including purchase, maintenance, and operations.

Fair enough. But a survey from Deloitte says that gas will have to reach $5 before EVs enter the mainstream. After interviewing 12,000 people worldwide (and over 1,000 people in the U.S.), Deloitte found that 78% of Americans surveyed would consider buying an EV if gas hit $5. But that’s not all: over 50% of Americans won’t pay a premium for EVs over their gas-powered counterparts. And over 77% of those surveyed expect to pay under
$30,000.

The $4.50 to $5 tipping point range seems reasonable, but yet another study from Cargurus.com says that gas will have to reach $7 a gallon on average for some hybrid EVs to break even in cost compared to gasoline-powered vehicles. The Toyota Camry hybrid will become cost-competitive at $4 a gallon, but the Cadillac Escalade hybrid won’t be competitive until gas prices hit $15 a gallon.

Then again, a recent Gallup poll found that 57% of Americans won’t buy an EV no matter how high gas prices get. So maybe there isn’t a tipping point at all.